This invention relates to a compact, implosion resistant, plastic reservoir of comparably large bulb volume for extended, relatively high temperature and vacuum use. In particular, the invention relates to such a reservoir that may be blow molded with partially hollow towers which enlarge its capacity and reinforce its mounting to active bodies such as car bodies.
It is well known that spherical bodies or bulbs are advantageous to withstand elevated pressure. Examples of metal and plastic spherical containers including blow molded containers appear in the following patents U.S. Pat. Nos. 3,029,963; 2,890,495; 2,818,191; 2,672,254; 2,462,064; 2,222,762; 2,106,494; 2,042,963. It is also known to construct mounting tabs for support of hollow bodies. For example, see U.S. Pat. Nos. 3,919,374; 3,514,812; 3,480,168; 3,343,210; 3,278,666; 3,145,686; 3,043,461 and 2,702,034.
It now, however, has been discovered that sturdily mountable, large sphere, hollow bodies for maintaining vacuum in such temperature environments as those encountered adjacent to automotive engine compartments may be economically fabricated from lower cost plastics, providing certain design criteria are followed.